6. Cushny and Peebles (1904) conducted a study on the effects of optical isomers of hyoscyamine hydrobromide in producing sleep. For one of the drugs, the additional hours of sleep for 10 patients were 0.7, −1.6, −0.2, −1.2, −0.1, 3.4, 3.7, 0.8, 0, and 2.